USFBully

Bought used 2002 Laredo that had a slow start up crank and figured it would be a fuel pump issue, changed out the fuel pump with one I found in a scrap yard and it appeared to solve the issue for about 2 days then it started exhibiting trouble symptoms with the start-up. More and more consistently the crank would take longer until it was every time except for when it was hot. Decided to buy a brand new fuel pump (perhaps the junk yard special was also defective). Installed last Thursday and by today the symptoms have slowly crept back to a predictable slow start-up.

If I changed the fuel pump twice and was able to get quick start-ups from cold for several days until the symptoms returned each time, then what could be the issue? I tested today after driving for about 30 minutes and it started right up twice in a row while still being hot from the drive.. Is the connection from the fuel pump faulty? the filter on the pump was new as well as the sending unit.

Really appreciate any help as this seems to be a common problem, but could not find an exact scenario like mine elsewhere on the internet.

go-part

Sounds like the fuel pump isnt getting the right amount of power sent to it. Have you checked the wires that connect to it?

I honestly think you have a bad fuel pump relay. It is located in your power distribution box, 3 blocks down on the far left

vadergator

check your cam position sensor. aka pick-up coil / relay. long crank time is a very common symptom. it usually turns into a no spark ( ain't going nowhere ) situation. sounds like you're almost there. it works in conjunction with your cps (crankshaft position sensor / crank sensor ) for your ignition timing and fuel delivery firing sequence on each one of your fuel injectors. you will start experiencing alot of stalling during warm up period and while accelerating if not changed. on my 97, it's in the distributor cap, underneath the rotor. flat, round disc with a magnet & wire that connects to wire harness. check for your location, since their 7 years apart. guarantee you that's what it is.:gunsmilie :

USFBully

thanks for the insight. I put some fuel solvent and it helped a little.. I'm thinking there is a blockage in the filter where the fuel pressure regulator is and working to replace it.. Will check other suggestions..

dave1123

You went to the trouble of installing a new pump and didn't change the filter? Why would you do that? The filter is probably plugged and the new pump forced enough fuel thru it for a while.

Oh, wait. Your filter is on the pump? When you had it out, was the tank clean? Is there water in it? IMO, put 2 cans of drygas in it and bounce it around. See if it starts better.

USFBully

just replaced the filter today, not the immediate result i had desired (quick start-ups) going to put another can of sea foam through it when I fill up again and see if i can't clean the fuel lines as best as possible to ensure that i cover my bases..

Turbo X_J

Before you replace anything else what are the codes?

USFBully

Please excuse my ignorance, but what codes are you referring to?

dave1123

He's asking about trouble codes from the self diagnostics in the PCM. They will show up as P codes in your mileage display. You have to turn the key on, off, on, off, on and wait.

USFBully

if these are the Chrysler diagnostic codes, then:

P0031
02 Sensor Heater Control Circuit Low (Bank 1 Sensor 1)
Shorted low condition detected in the oxygen sensor 1/1 heater elementcontrol feedback sense circuit

P0051
02 Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
Shorted condition detected in the oxygen sensor heater element control feedback sense circuit.

P0136
O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
An open or shorted condition detected in the ASD or CNG shutoff relay control ckt.

P0456 (M)
Evaporative Emission Control System Leak Detected (very small leak)
A 0.020 leak has been detected in the evaporative system. See TSB's 25-001-02A, 18-002-03 and 25-004-01. Also, possible faulty or loose gas cap.
(Also see Notes in P0455 above). Does customer regularly commute on a steep grade (down hill grades in excess of 10%? Has the Leak Detection Pump Operation and Diagnosis booklet (Publication No. 81-170-000606) been used to assist in the diagnosis?
Review and if necessary, perform TSB 18-010-02. Be sure to completely read the TSB. The fix for the condition is a PCM replacement, not a reprogramming of the controller. Be sure that there is not any leaks in the system. This TSB applies in a very limited number of cases and usually in mountainous regions. TSB 18-010-02 Is a PCM replacement correct an erroneous MIL illumination for SAE P0456 that sets when driven on steep grades.

P1281
Engine is Cold Too Long
Engine coolant temperature remains below normal operating temperatures during vehicle travel (Thermostat).


(P1282 is fuel pump relay which was my guess. I got a new one and was going to replace tonight, but it's pouring rain outside right now..)

USFBully

Still no change with changing the fuel pump relay. I'm thinking of caving and just taking her to a mechanic, but last time I did that he said it was a fuel pump issue and would cost me an arm and a leg. I'm just confused because when I changed the fuel pump both times it appeared to work fine for a day or two and then it fell back into the same problems..

Turbo X_J

What is the fuel pressure in PSI? (If you don't have a gauge you can borrow one from autozone and the like). How long has it been since the O2 sensors were replaced, is the wiring in good shape? Fuel cap goes without saying just replace it.

USFBully

put a different cleaner through the fuel system, worked well for the entire tank of gas, now its back to square one. I think i'll just cave and take her to a mechanic to have them check the fuel lines and pressure.. can't wait to see a bill for this one.

USFBully

I there a chance that the problem is rooting from faulty or clogged fuel injectors? As I said when I run fuel injector/ system solvents throught the system the car will start well for that tank of gas. I have pretty much ruled out the chance of it being a fuel pump issue since I have put 3 different sets of pumps and filters in and changed the fuel pump relay as well. A mechanic definitely noted a decrease in pressure below normal when the car is shut off, is it leaking pressure front the fuel rail/ injectors then?

grn99

Check the battery? Maybe I missed something but I usually start simple.